Delay Tolerant networks (DTNs) are one type of wireless networks where the number of nodes per unit area is small and hence the connectivity between the nodes is intermittent. In this case, the performance in terms of transport of information from source to destination relies on the mobility of the nodes which would cause their encounters and hence the relay of information from one node to another as well as on the routing protocol that is deployed. There exists several mobility patterns, each yielding a different performance of the network. In this work, we show first that the Manhattan mobility pattern performs worse than other widely-used ones, such as Random WayPoint. In the second part of this work, our aim is to propose and evaluate a new proposal, based on the deployment of fixed relays, so as to enhance the performance of Manhattan